苎麻根际抗Cd细菌筛选及对苎麻生长和吸收Cd能力的影响

本文报道从苎麻根际筛选出5株抗Cd细菌（cdr1、cdr2、cdr3、cdr6、cdr7）,通过16SrRNA基因序列分析结果显示,cdr1和cdr3属于金黄杆菌属（Chryseobacterium）,cdr2属于农杆菌属（Agrobacterium）,cdr6属于贪噬菌属（Variovorax）,cdr7属于黄杆菌属（Flavobacterium）。采用盒栽试验方法,研究了抗Cd细菌对苎麻生长和吸收Cd能力的影响。结果表明,在Cd添加量为10mg·kg^-1土壤中接种cdr6、cdr7能显著增加苎麻生物量和叶片叶绿素含量,降低植株地下部分丙二醛（MDA）含量,但对植株Cd含量没有影响。从平均值来看,接种cdr1和cdr3的苎麻株高低于对照,但只有接种cdr3的处理达到显著水平。接种cdr1和cdr3的苎麻地上和地下部分干重、叶片叶绿素含量均低于对照CK-1,但其差异均没有达到统计意义的显著水平。接种cdr1、cdr3的苎麻地上部分Cd含量显著高于对照CK-1。接种cdr2对苎麻植株生物量和Cd含量均没有显著影响。

Isolating Cd Resistant Bacteria from Ramie Rhizosphere and Their Effects on the Growth and Cd Absorptional Characters of Ramie

This paper first reports five Cd resistant bacteria strains isolated from rhizosphere of ramie. Sequences of 16 S rRNA gene suggested cdr1and cdr3 belonged to Chryseobacterium, cdr2 belonged to Agrobacterium, cdr6 and cdr7 belonged to Variovorax and Flavobacterium respectively. The results of pot experiment showed that Inoculation of cdr6 and cdr7 increased biomasses and Chlorophyll contents of ramie in the soil which amended 10 mg·kg-1 Cd. And also, cdr6 and cdr7 could decrease the contents of malodialdehyde（MDA）in the roots, but have no effects on the absorption of Cd both in the shoots and roots in this soil. The stem lengths which inoculated cdr1 and cdr3 were lower than the control, but only the treatment which inoculated cdr3 reached static significant level. The means of biomasses and Chlorophyll contents of ramie were lower than the control when inoculated cdr1 and cdr3, but these differences were not reached static significant level. Cd contents in the shoots were significantly higher than the controls′ when inoculated cdr1 and cdr3. There was no effect on the biomasses, Chlorophyll contents, and Cd content when inoculated cdr2 in this Cd contaminated soil.